UNLABELLED: Concerns regarding the potential negative impacts of digital technology use on youth mental health and well-being are high. However, most studies have several methodological limitations: relying on cross-sectional designs and retrospective reports, assessing technology use as an omnibus construct, and focusing on between- instead of within-person comparisons. This study addresses these limitations by prospectively following young adolescents (n = 388) over a 14-day ecological momentary assessment study to test whether adolescents digital technology use is linked with self-reported emotional dysregulation and self-esteem and whether these relationships are stronger for adolescent girls than boys. We found no evidence that adolescents experienced higher emotional dysregulation (b = - .02; p = .07) and lower self-esteem (b = .004; p = .32) than they normally do on days where they use more technology than they normally do (within-person). Adolescents with higher average daily technology use over the study period did not experience lower levels of self-esteem (between-person, b = - .02; p = .13). Adolescents with higher average daily technology use across the two-week period did report higher levels of emotional dysregulation (p = .01), albeit the between-person relation was small (b = .08). There was no evidence that gender moderated the associations, both between and within adolescents (bs = - .02-.13, p = .06 - .55). Our findings contribute to the growing counter-narrative that technology use does not have as large of an impact on adolescents mental health and well-being as the public is concerned about. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42761-024-00282-w.